Method of and apparatus for preventing warping and twisting of lumber during kilning.



n. R. TANNER. I METHOD OF AND APPARATUS FOR PREVENTING WARFING ANDTWIS'HNG OF'LUMBER DURING KILNING.

' APPLICATION FILED FEB. 2*,196- 1,212,583. U PatentedJan. 16,1917.

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0.11. TANNER. v METHOD OF AND APPARATUS FOR PREVENTING WARPING ANDTWISTING 0F LUMBER DURING KILNING.

APPLICATION FILED FEB. 24, l9l6- Patented Jam-.16, 1917.

3 SHEETS- SHEET 2.

" flwizan Q N NU D.R.TANNI ER. I 1 METHOD OF AND APPARATUS FORPREVENTING WARPING AND TWISTING'OF LUMBER DURING KILNING,

APPLICATION FILED FEB. 24, I9I6- Patented Jan. 16,191].

3 SHEETS-SHEET 3.

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- Iii a l s'rAs PA i DANIEL R. TANNER, OF LA GRANDE, OREGON.

METHOD OF AND APPARATUS FOR PREVENTING WARPING AND TWISTING OF LUMBERDURING KILNING.

Patented Jan. 16, 1917.

Application filed February 24, 1916. Serial No. 80,316.

To all whom it may concern Be it known that I, DANIEL R. TANNER,residing at La Grande, in the county of Union and State of Oregon,United States of America, have invented new and useful" Improvements inMethods and Apparatus for Preventing Warping and Twisting of LumberDuring Kilning, of which the following is aspecification.

This invention has for its object the provision of improved means forpreventing lumber from twisting when the lumber is being dried orkilned.

It has been determined that a tree exposed to the rays of the sun willtwist in the direction in which the sun moves about the tree. \Vhen thetree or log is sawed up into boards, the green boards will be flat, butwhen these boards are dried or kilned they will twist 'in the directionin which the log, from which they were sawed, was twisted by the sun.Trees not exposed to the suns rays will not twist but the lumber from aplurality of logs is never assorted to segregate the lumber withinherent twist from lumber without such twist and therefore when a stackof boards is closely held in compact form, those boards which twistmally dry fiat.

during the drying operation will not only distort themselves from trueplanes but will distort adjacent boards that would nor- The drying orkilning of lumber not only initiates twist of certain kinds of stock butwarping of all kinds of stock and if the lumber is permitted to eithertwist or warp when kilned, it will be graded low and the resultant losswill be very great.

It is one of the primary objects of this invention to provide means forembracing a stack of lumber .during the kilning operation, andholding-the lumber in such compact pressure engagement and abuttingrelation as not only to prevent warping but' degrees so as toautomatically 'act at different long tudinal and vertically elevatedpoints on the load with varying or different degrees of pressure in sucha manner that the finished kilned stack will'be rectangular instead oftrapezoidal in cross sections, which latter form it would take if thelumber were permitted to twist when kilned.

An interdependent function to the foregoing, is that of not onlypreventing twist, but at the same time, preventing the lumber fromwarping, and also,holding the-lumber under such sustained pressure thatwhen the boards dry and their edges space apart as a result ofshrinkage, the lumber will be prevented from collapsing into contact andadjacent edges willbe sustained in spaced relation so that all areas ofeach board will be exposed to the kilning action.

A special feature of novelty consists in providing each stake of eachpair or set with an independently tiltable pocket or holder, the pocketsof each stake set being connected by actuating meanswhich is adjustablefor the purpose of causing the upper end of one stake to exert a greaterdegree of restraint or resistance against lumber twist than the lowerend of such stake, the said means causing the companion stake to exert agreater resistance against twist at its lower end than at its upper end.

In practice, lumber twist initiates from the longitudinal verticalcenter of the stack and increases toward the ends of the stack, and oneend of the stack will seek to twistin one direction whereas the otherend of the stack will seek to twist in a direction reverse to the firstnamed direct-ion.

' Now, in accordance with my improved method and structure, I can adjustsets of stakes from the central set toward the end sets in increasinggradations in accordance with the gradation of increase of twist andalso in accordance with the reversal of twist, end to end, so ascompletely to eliminate any distortion of the stack fram a truerectangular cross section during the kilning operation. v

.Other features of novelty will be more fully described in connectionwith the accompanying drawings and will be more particularly pointed outin and by the appended claims.

In the drawings :Figure 1 is a vertical 7 2 is a view in elevationlooking from the left of Fig. 1. Fig. 3'is. a sectional view similar tothe lower portion of that shown in Fig. 1 illustrating the difierencebetween a central or neutral adjustment and an end adjustment. Fig. .4'is a view similar to Fig. 3 showing the reverse adjustment for theopposite end with the parts released so that the stakes will exercisepressure engagement on the load. Fig. 5 is a horizontal sectional viewtaken on line 5-5 of Fig. 4,

. with the lumber omitted. Fig. 6 is a secview of a stac of lumbershowing in full lines how ;the' device of my invention prevents twist,and showing in dotted lines,.in

greatly exaggerated form how the lumber would twist without the deviceof my invention. Fig. 12 is view in end elevation showing in full lines"how the device of my invention prevents lumber twist, and in dottedlines how the lumber would twist in the absenceof my improvedapparatus.

Like characters of reference designate similar parts throughout thedifierent figures of the drawings.

As illustrated, the device of my invention is in the form of a lumbercarrier comprising a plurality of. bolsters, each of which is shownformed of lengths of channel iron 1. Each bolster of the carrier ismountedupon a pair of truck units and each truck unit comprises a, truckbolster 2 supported upon truck wheels 3, the latter being adapted to runupon rail 4. The foregoing comprises alumber carrier, asa whole, uponwhich the lumber may be stacked. In order to sustain the lumber in edgedstacked form, each carrier bolster is provided with a pair or set ofstakes 5 extending verticallyv along opposite sides of the load atspaced points there along as indicated in Fig. 2. The lumber 6 isstacked on edge and stickers 7 are interposed between each stacked tierto hold the adjacent sides of tiers in spaced relation in order toexpose lateral areas of the boards to the kilning action.

The stakes 5 are shown formed of I-beams and the webs at the upper endsare notched at 8 to receive chain loops 9, the chain loops 9 beingconnected with chains 10 and 11. In chain 10 there is interposed acontractile spring 12, as shown in Fig. 1. Chain 11 is provided with atogglelever take-up which comprises a lever 13 pivoted at 14 to oneportion of chain sectionll and pivoted at-15 to another section of chain11. When the carrier has been stacked with lumber each pair or set ofstakes is yieldingly connected by this spring take-up when the lever 13is thrown into the position shown in Fig. 1, with the pivots 14 and15'beyond dead center relation thereby sustaining the upper ends of apair of stakes in pressure engagement against opposite sides of theload.

Reference will next be made to the novel means of pocketing, and tensionactuating the lower ends of the set of stakes.

Each carrier bolster composed the chan-- nels 1 is made rigid by bolts16 which pass through the webs of the channels 1 and also throughabutment spacing members 17 thereby rigidly connecting the channels 1 insuitable spaced relation. The abutment members 17 have upper and lowerprojections 18 and 19, each provided with adjustable -pocket abutmentswhich may be in the form of oval ended screws 20 and 21. A

pocket is provided [for each stake and as.

all pockets are identical in structure and oporation only one need bedescribed in detail. j

, Referring to Figs. 5 to 7, each pocket comprises upper and lowertilting members 22 and 23, respectively, through which the stake 5projects, and the lower member 23 direction in a single plane withrespect'to atrue vertical position. It will thus be seen that the'pocket structure tiltably engages the carrier bolster, above and belowthe same in such a manner as to be efiectively supported thereby. f p

' The pocket comprises stakeholding portions 29 and 30 which extendvertically between the channels 1 and which are preferably formedintegral with the upper and lower members 22 and '23. Said holdingmembers 29 and 30 embrace the stake flanges on opposite sidesas'indicated at 31 and 32. Extending inwardlyfrom the holding member 29,of the pocket, is a yoke having upper and lower lengths 33 and 34 whicharejoined by a bight 35. The upper length 33'is slotted at 36 and alongthe member 29 and lower ler'1gth'34 I arrange elevated cam witheccentrically disposed trunnions 40 which are journaled inthe 'webs ofchannels tracks 37 and 38. The cam 39 is provided rec ' having thespring 45 fioatingly free,

I manner that it may be rotated about justing member 43 is mounted insuch :1 its own axis without being shifted axially. To each linkadjusting member there is applied a link or strap designated at 44, tothe inner ends of which is connected a contractile spring 45 havingtension power considerably in excess ofspring 12.

The function of the spring 45 is to contract or embrace its set ofstakes against opposite sides of the load so that when the latter issubjected to tension the stakes on each side will have take-up actuationand therefore it will not be necessary to shift the entire loadlaterally in order to take up slack of shrinkage reduction in volume.lily t e stakes on opposite sides will each only shift a portion of theload into compact relation. I When the cams are in the position shown inFig. 3, and also in Fig. 1, the springs 45 are distended and the stakes5 are posi-. tively held by the cams not only in spaced relation but inengagement with the end abutment 17 in such a manner stakes will betruly vertical. In this position, the cams will be rotated with theirgreatest diameters in engagement with tracks 37 and slightly beyond adead center position, adjustment being limited beyond such dead centerposition by tracks 38 against which the cams are forced downwardly. Whenthe carrier is loaded and ready to be run into the kiln, then the camsare released in a clock-wise direction from the position shown in Fig.3, to the position shown in Fig. 4. The springs 45 instantly act to movethe pockets inwardly from the abutments 17 and in such spaced relationthereto that the pockets will be unrestrained by the abutment plates,and will be free to have exerted thereon such differential action as thesprings are adjusted to impart.

I will next describe one of the most important features of the inventionwhereby unequal tension stress is exerted by the springs a set to exerta greater pressure on the load than the other end of such stake, and tocause a reverse action or stress tension on the companion stake of suchset.

In Fig. 1 the links 44 are adjusted to a true horizontal positionbecause the stakes which this spring actuates are in the middle of theload, longitudinally-speaking. There fore, the central stakes 5, asshown in Fig. 1, will be under tension throughout their entire height toexert a uniform stress against the load. These central upon to corrector prevent twist but merely to prevent warping of the lumber when thesame dries.

In Fig. 3 I have shown the adjustment which would be made at one extremeend of the load, such adjustment being effected that the p 45 to causeone end of one stake of,

stakes are not called by turning adjusting screws 43 to elevate thelinks 44 at one side and correspondingly lower the opposite link so asto dispose the spring 45 at an angle to the horizontal. Now referring toFig. 3, it will be clear that the upper end of the left hand stake 5will exert a greater pressure against the load than the lower end ofsuch stake. Inversely, the lower end of the right hand stake of Fig. 5would exercise a greater stress or pressure against the load than theupper end of said right hand'stake. At the opposite end of, the load, aswill be seen by reference to Fig. 4, the left hand link 44 is adjusteddownwardly and the right hand link is adjustedupwardly. Thus the lowerend of the left hand stake would exert a greater pressure than the upperend of such stake, and inversely, with respect to the right hand stakeof Fig. 4. At this point, I wish to make it clear that the difference ofpressure exerted by the stakes at different elevational and longitudinalpoints along the load is not sutficient to shift the stakes out of avertical position, except perhaps temporarily, where such shiftingmovement is caused by the twisting lumber itself shifting the stakesfrom a normal or true vertical position, the tilting pockets affordingthis movement. The main point is that the actuating mechanism for eachset of stakes is adjusted to impart differential action of said stakes,toward the endmost stakes, will be adjusted in graduated degrees fromthe neutral adjustment shown in Fig. 1 toward the adjustment at one end,as shown in Fig. 3, or reversely toward theother end, as shown in Fig.4. In other words, the' slant of the links 44 of that set of stakes nextadjacent the endmost stakes shown in Fig. 3 will be slanted at the sameinclination but not to the same degree from the horizontal, as theadjustment in Fig. 3 for the reason that the greater extent of twistwill be nearest the end of the load.

In Fig. 10 I have shown a log spirally lined to indicate the directionof twist.

Figs. 11 and 12 graphically illustrate the manner in which the loadwould twist from a true rectangular cross section if the lumher were notrestrained. In this connection, it is desired to emphasize the fact thateven if a majority of the boards were of a character to dry flat, themoiety of boards having aninherent twist would distort all of the otherboards of the load from true fiat condition.

It will be understood that the problem and the adjustment effected willact stakes parallel. Those presented, and which this invention hassolved, is not present in cases where lumber i is loosely piled to forma. load and then sub jected to the action of the kiln but only where itis attempted to hold the lumber in flat abutting relation.

By reason of the fact that the springs 45 are much stronger than thesprings 12,

they will exercise a controlling moment in applying stress to the stakesand the springs 12 will conform and supplement the action of springs 45.

By reason of the fact that the polygonal trunnion ends 41 are notreadily accessible after the carrier. is loaded, and by reason of thetremendous stress exercised by the springs 45 when the cams arepartially released, I find it desirable to provide a special type of camactuating wrench which is designed to not only take care of theforegoing requirements but also to prevent dangerous kicking which mightinjure the operator.

Referring more particularly to Figs; 8 and 9, 46 designates a wrench orratchet frame which may be made in two parts and which is shown suitablyconnected as by a bolt 47. Looking at Fig. 8, one dimension of saidframe is such that the frame will fit snugly between the flanges of the'chan-.

nels 1 to provide a locking anchorage, the purpose of which willpresently appear. A ratchet wheel 48, having ratchet teeth, is

. rotatively mounted in said frameby means of hollow trunnions 49 whichextend through spacing blocks 50 and through said frame. The entireratchet structure 48 is provided with a polygonal board 51 adapted totake. over or receive one of the polygonal ends 41 when the wrench isap-' plied against the web of one of the channels wheel.

1. The wrench is provided with a handle.

52 of suflicient length to project beyond the truck or carrier and beaccessible to the operator. Said handle 52 is bolted by bolts 53 to bars54 and the latter are journaledon the trunnions of the ratchet wheel 48to loosely oscilate thereon. A ratchet pawl 55 is journaled on a pin 56so as to be actuated upon movement ofv the handle. A spring 57, anchoredat 58 on the handle, engages said pawl at 59 to hold the pawl inengagement with the teeth of the ratchet A reversely disposed pawl 60 isjournaled on a pin 61 for engagement with the ratchet teeth inopposition to the pawl 55. A spring 62, anchored at 63, engages saidpawl 60 at 64, to hold the same in engagement with said ratchet wheel.

The wrench may be applied with the pawl 55 uppermost or lowermost inaccordance with the direction in which the spacing cam is to be rotated.If for instance the spacing cam is to be rotated from the position shownin Fig. 3 to the position shown in Fig. 4, the "wrench will be appliedwith the pawl 55 uppermost. After the cam has naiaeea be actuated by thetremendous force of spring 45 until it reaches the position shown inFig. 4. During this spring actuation of the cam, which is very violent,the ratchet Wheel '48 will run. wild thereby saving the operator frominjury. If the cam is to be turned from the position shown in Fig. 4 tothe position shown in Fig. 3, then the Wrench will be applied to disposethe pawl 55 lowermost and the pawl 60 will lock the ratchet wheelagainst return movement at each oscillation of the handle 52 in backingthe pawl 55 for engagement with an advance tooth.

It will be seen from the foregoing that my improved method consists inimparting differential and varying pressure at spaced longitudinal andelevational points along 0 the lumber load to prevent a load of compactlumber from twisting during the kilning action.

It is believedthat my improved method and apparatus will be fullyunderstood from the foregoing description, and while I have shownspecific forms thereof, 1 do -follow-up action at difierent points alongthe load of material during shrinkage and irrespective of the reductionof volume thereof and also exerting a variable pressure at differentlongitudinal and elevational points along the load, whereby the lumberis prevented both from warping and also twisting during the 'ngoperation, substantially as described.

In a mechanism for preventing twisting of lumber during drying,apparatus exerting a substantially constant follow-up pressure withvariable action at difierent longitudinal and elevational points alongthe load of lumber, whereby the lumber is prevented from twisting duringthe drying operation, substantially as described.

a mechanism for preventing twisting of lumber during drying, apparatusexerting a substantially constant follow-up pressure on both sides ofthe load of lumber and with variable action at difi'erent longitudinaland elevational points on both sides thereof thereby preventing twistingof the lumber while it is drying, substantially as described.

4. In a mechanism for preventing twisting of lumber during drying,apparatus exerting a substantially constant follow-up reseure on bothsides of the load of lumer and at the top and bottom of such sides witha variable action at different longitudinal and elevation points on bothsides thereof, thereby preventing twisting of the lumber during drying,substantially as described.

5. In a mechanism for preventing warping and twisting of lumber duringdrying, apparatus exerting a substantially constant follow-up pressureat difierent points along both sides of a rectangular load of lumber tobe dried and irrespective of variation of shrinkage and reduction ofvolume and also exerting stress in different directions at opposite endsof the load to prevent twisting during drying of the lumber,substantially as described.

6. In a mechanism for preventing warping and twisting of lumber duringdrying, apparatus applying parts'of a lumber load in opposition toshrinkage twisting stress distortion of the lumber during drying toprevent twisting of boards in one portion of the load from distortingboards which would otherwise dry flat, substantially as described.

7 In a mechanism for preventing ing of lumber during k'lning, means-forsupporting the lumber to be kilned, a plurality of independent sets ofactuated stakes gripping the load on opposite sides and at spaced pointstherealong to take up shrinkage irrespective of variation or volume, andan. independent mechanism for each set of stakes for actuating the stakesets near one end of the load to prevent lumber twist in one directionand to actuate stake sets near the other end to prevent lumber twist ina direction opposite from the first named direction, substantially asdescribed.

8. In a mechanism for preventing twisting of lumber during kilning,means for supporting the lumber, a plurality of sets of independentstakes engagingthe load on opposite sides thereof, an independentadjusting mechanism for each set of stakes, and means for adjusting themechanisms of said sets from the central set toward the end sets inincreasing gradation to cause those sets .on one side of said centralset to resist twist shrinkage of the lumberin one direction and thosesets on the other side of said central set to resist shrinkage twist ina direction opposite from said first named direction, substantially asdescribed.

9. In lumber during kilning, means for supporting the lumber, aplurality of sets of stakes engaging the lumber load on opposite sidesthereof, an independently adjustable stake actuating mechanism foreachset of stakes, and means for adjusting the mechanism of one set ofstakes to cause the upper end of one stake of such set to exert agreater resistance against lumber twist than the lower end of such saidstake, and vice versa as repressure to differenttwista mechanism forpreventing twist of mounted in each pocket, a cam each pocket androtatively mounted in said gards the companion stake of such set asregards the upperand lower ends thereof, substantially as described. v

10. In a mechanism for preventing the twisting of lumber during kilning,means for supporting the lumber, a engaging the load on opposite sidesthereof, -a tiltable pocket for each stake, and means acting throughsaid (pockets to apply follow- I up tension on sai stakes and tilt saidpockets to cause the upper end of one stake to exert a greaterresistance against shrinkage twist than the lower end of such saidstake, and vice versa as regards the upper and lower ends of the otherstake of said set, substantially as described.

11. In a mechanism of the class described,

set of stakes for means for supporting the lumber to be 7 kilned, stakesengaging the load on opposite sides, and floating means for urgingopposed stakes against said load, substantially as described. J

12. In a mechanism of the class described, means for supporting thelumber to be kilned, stakes engaging the load on opposite sides,floating means against. said load, and independent devices forretracting said stakes away from said load, substantially as described.

13. In a mechanism of the class described, means for I supportingthelumber to be kilned, stakes tiltably mounted on said means forengaging the load on opposite sides, and floating means urging opposedstakes against said load, substantially as described.

14. In a mechanism of the class described, means for supporting thelumber to be kilned, stake abutments on said means, stakes tiltablymounted on said means, floating mechanism for urging opposed stakesagainst said load, and independent devices for shifturging opposedstakes.

ing said stakes away from said load and 7 against said abutments,substantially as described.

15. In a mechanism of the class described, means for supporting thelumber to be kilned, stake abutments on said means, stakestiltablymounted on said means, mechanism urging said stakes againstopposite sides of said load, and devices for shifting said stakes awayfrom said load and into rigid positions against said abutments,substantially as described.

16. In a mechanism for preventing lumber from twisting during kilning, acarrier bolster for supporting the lumber to be kilned, a stake pocketslidably and tiltably astake for actuating mounted on each end of saidbolster,

bolster, a spring for each pair of pockets to contract said stakesagainst opposite sides of the load, and devices foradjustably connectingsaid spring, with said pockets to alter the direction ofcontracting-pull of bolster! for supporting the lumber to be kilned,astake pocket slidably and tiltably mounted on said bolster at each endthereof, a stake in each pocket, a spring for each pair of pockets tocontract the, stakes thereof against said load, and devices foradjustably connecting said spring with said pockets to alter thedirection of pull of said spring and thereby vary the on said load toprevent twist of the lumber, substantially as described.

18. In a mechanism'for. preventing luma her from twisting duringkilning, means for supporting the lumber to be kilned, stakes engagingthe load on *opposite sides thereof, minor spring take-up means actuat-,

ing the stakes at one endthereof to compress the load, and major springtake-up means actuating the opposite ends of the stakes to cause thelatter to resist and prevent distortion of the load from twist of thelumber, substantially. as described.

19. The herein described method of con trolling lumber during kilning,which consists, in holding the load under compression during kilning andexerting pressure on certain. parts of the load in excess of thepressure on other parts to prevent distortion of the load undertwistingaction of the lumber during kilning, substantially as described.

20. The herein described method of controlling lumber during kilning,which consists, in holding the .load under compression during kilningwith a constant pressure uniformly exerted along the load at spaced"longitudinally to prevent the action of the stakes twisting during'shrinka e.

ing action of the lumber during kilning, substantially as described.

21. The herein described method of controlling lumber during kilning,which consists, in holding the load under compression during kilningwith a constant pressure substantially uni ormly exerted atspaced pointsand vertically along the load lumber from warping during kiln shrinkage,and in exerting pressure at selected points along the load in excess ofand in graduated degrees to prevent distortion of the load undertwisting action of the lumber during kilning, substantially asdescribed.

22. The herein described method of controlling lumber duringkilning,which condegrees of pressure exerted in diflrent directions and duringshrinkage to prevent 23, In a mechanism or holding lumber under pressureduring kilning, a bolster for supporting the lumber comprising channels,stakes mounted on said channels for gripping the load, means rotativelyjournaled in said bolster for shifting one of said stakes out ofengagement with the load, and ratchet wrench mechanism noh-rotativelyand interchangeably fitting between the flanges of said bolster forrotating said means in either of two directions, substantially asdescribed.

In testimony that I claimthe foregoing as my own, I hereby aflixmy'signature.

DANIEL R. TANNER.

sists, in holding the load underdiflerent said uniform pressure indifferent directions

